Samsung ships Galaxy S5 Mini in volume using Exynos 3470

S5 Mini shipping with lower performance SoC

Not long ago, Samsung announced the Galaxy S5 Mini, a smaller and somewhat cheaper version of the Galaxy S5, which similar external design and software features, which is now starting to ship in volume Europe.

Although marketed not far below the Galaxy S5's spot in the higher-priced segment, the Galaxy S5 Mini contains Samsung's Exynos 3470 SoC, a chip with a CPU and GPU configuration more reminiscent of lower-priced devices, with considerably less performance potential than the Qualcomm Snapdragon 800 series chips used in the Galaxy S5, and potentially lower than competing mid-range devices utilizing chips from Qualcomm's Snapdragon 400 series.

Whether this will affect its sales performance is debatable, because most end users are not likely to notice lesser maximum performance in demanding games or benchmarks, as long as performance, smoothness and battery life remain appealing for every-day use, while the Samsung Galaxy S5 branding and design is likely to be attractive in the market. Some early reviews seem to be positive regarding user experience.

Features of Exynos 3470

Although the Exynos 3470 is labeled as being part of the Exynos 3 series, which further includes an ancient single-core Exynos 3110 application processor SoC that is several years old, it is in fact a newly designed chip manufactured using Samsung's 28nm process (probably not much different from the one used for the much more complex Apple A7 chip). It is the first Exynos chip to exclusively use a quad-core ARM Cortex-A7 CPU configuration (clocked at 1.4 GHz), that due its superior performance characteristics (consisting of low cost and die area, low power consumption and adequate performance) has already been widely adopted by MediaTek and Qualcomm and currently dominates the entire entry-level and mainstream segments of the smartphone market.

Current information points to the use of an integrated 2G/3G/4G baseband inside the Exynos 3470, which is a first for a mainstream mobile Samsung SoC. In fact Samsung's web-page describing its new Exynos ModAP series, although very general, seems to match the specifications of the Exynos 3470 and S5 Mini. Being a new modem implementation of unknown origin, closer examination of the Exynos 3470 and S5 Mini's cellular radio performance (such as voice and data reception) will be enlightening. Along with Samsung's use of an Intel modem chip in the Galaxy Alpha, the S5 mini seems to confirm a clear trend away from Qualcomm baseband (as well as application processor) technology at Samsung. The timing will be helpful for Samsung and the industry because it can alleviate the current shortage of smartphone SoCs produced at TSMC.

S5 Mini design choices balancing performance with cost

The use of a single 1.5GB LPDDR3 DRAM package (presumably containing one 12Gbit chip) is economical, approaching the current sweet spot for gains in Android system performance with lower cost than 2GB DRAM. The maximum 6.4GB/s memory bandwidth mentioned by Samsung points to the use of a single-channel 32-bit LPDDR3 memory interface at a maximum rate of 800 MHz, lower than high-end dual-channel platforms such Snapdragon 800, but probably somewhat higher (depending on the actual memory clock used in the S5 Mini) than typical configurations used by Snapdragon 400 and MediaTek platforms.

By user a lower resolution 720p display instead of 1080p used in the Galaxy S5,  Samsung significantly reduces the burden on the CPU, GPU and memory subsystem, which is highly important given the much lower performance headroom of the Exynos 3470 platform, especially the GPU and memory subsystem.

Mali-400 MP GPU still viable, even for mid-segment

The new chip illustrates the remarkable longevity of ARM's Mali-400 MP GPU core, many years after its introduction. With its ARM Mali-400 MP4 GPU (a four core configuration), the Exynos 3470 uses the same GPU architecture as much older Exynos chips that were already used in devices such as the Galaxy S II several years ago, although at the higher clock speed permitted by the current 28nm process. The Mali-400 MP GPU architecture currently has a dominant position in the SoC market for entry-level smartphones through chips such as MediaTek's MT6572 (single Mali-400 core) and MT6582 (two cores) as as well as most of the tablet market through Rockchip's RK3188(T) (four cores) and various other products from companies such as MediaTek and Allwinner. It will probably continue to be used for some time, and is still being designed into new chips such as Allwinner's A33 with Mali-400 MP2 targeting low-end tablets.

Update of December 5, 2014

Making a count of Geekbench entries of Exynos 3470 vs Snapdragon 400-based models after a number of months of production should given an indication of the level of production of Exynos 3470 for the Samsung Galaxy S5 Mini. The following is apparent:

• The Exynos 3470-based SM-G800R4 has a count of 4, SM-G800M a count of 17, SM-G800Y a count of 7, SM-G800F a count of 383.
• The Snapdragon 400-based SM-G800A has a count of 8, SM-G800H a count of 210.

Although Exynos 3470-based entries hold the clear majority, the overall number of entries a relatively low, many times lower than that of the Galaxy Note 4 also significantly lower that the number of entries for the Galaxy Alpha. However, the average buyer of a Galaxy S5 Mini is probably much less likely to run Geekbench on their device, so the actual number sold in comparison with the mentioned high-end models may be greater than it seems.

Sources: Wikipedia, iFixit, Samsung, CHIP (German)

Updated December 5, 2014.